It's generally a bad idea to assume crimes were committed when there is no evidence. And when there's evidence leading to a suspect's arrest, it's still improper to assume that person's guilt.

Even so, learning that New Orleans police officer Christopher Buckley was investigated in 2001 and 2003 -- once for raping a child and once for raping two children -- before being arrested Tuesday on the suspicion that he repeatedly raped a child this year will make New Orleanians doubt that Buckley was a model officer during the intervening years.

Local residents want all violent criminals prosecuted and want all bad officers off the police force, but somehow Buckley managed to keep his job and avoid prosecution for seven years after the first accusation. He resigned his position with the Police Department after his Tuesday arrrest.

It appears that both Richard Pennington's and Eddie Compass' administrations left it to Superintendent Warren Riley to be publicly embarrassed by the arrest of an alleged sexual predator with a badge. Also, two district attorneys declined to pursue charges against the officer.

After the 10-year veteran was booked this week for allegedly raping the 13-year-old daughter of an acquaintance, Riley said Buckley "should never walk the streets again."

Maybe little girls in New Orleans would have been safer if Buckley's ability to walk the streets had been curtailed years ago, but twice police officials sent accusations against Buckley to the Orleans Parish district attorney's office, and twice that office found a reason not to prosecute him. When prosecutors refused the charges police officials did nothing.

Harry Connick's office chose not to prosecute the 2001 rape allegation, and Eddie Jordan's office chose not to prosecute the rape allegation from 2003. Riley said both times the Police Department provided witness statements and evidence but that in both cases prosecutors cited the "failure of the victims or the victims' parents" to cooperate.

If it's true that the girls themselves or their parents made it impossible for prosecutors to make cases against Buckley, one would expect records in the district attorney's office to reflect that, and one would expect the district attorney's office to leap at the opportunity to say its hands were tied.

But when asked Wednesday to explain the office's previous decisions regarding Buckley, a spokeswoman declined to talk, saying her office "cannot comment on any current or prior cases involving Mr. Buckley."

No matter what the district attorney's office decided to do, New Orleanians want their police officers held to a high standard, and an officer repeatedly being accused of raping little girls is falling far short of it. Pennington and Compass could have conducted an administrative investigation to address the accusations against Buckley and made the officer testify.

Because there's a constitutional prohibition against self-incrimination, that information could not have been used in a criminal case against Buckley, but that shouldn't have concerned police officials given that prosecutors had already rejected the cases.

In acknowledgment that a really bad police officer can manage to avoid criminal prosecution, Riley is working on a plan that would help him pinpoint officers repeatedly accused of wrongdoing so as to have them removed from the force.

There's always the chance that an officer could be falsely accused of wrongdoing. But it is far less likely that multiple people over a period of years would make similar allegations against an officer and all of those allegations be false. What good officer finds himself repeatedly accused of raping little girls?

And if it turns out that Buckley is as bad as the accusations against him suggest, the public will certainly wonder if there are other little girls who have never come forward.

Jarvis DeBerry is an editorial writer. He can be reached at 504.826.3355 or at jdeberry@timespicayune.com.